Spark plug



H. F. STEPHENSON.

SPARK PLUG.

Awumrzor: mw re. m2o,

ziented June ZU, w22.

@woz/Mag o entre?.

Specification of .Letters latent.

.irppliciiton .oiled April 1G, 1952@ Serial No. 374.439.

To all 11i/0m al 1214// concern:

.Be it knon'nthat l. Ronnn'r h 'rnriinnson', a citizen of the United Stneo, residing at .flug-until. in the county or'BuLler, State ol. Kansas.' have invented a new and useful improvement in ipixrli Plugs, which the following is u speeiliezition. v

This invention .relates to on improved spurl; plug und one ohjeelc or the invention i5 to provide u. plug which will beeelf cleaning und in Vwhich n spark will serre to burn earhon oll` of he plug in cose any should attempt ro ueeui'nulate thereon.

Another object of the invention is lo pio Vido :1 plug which ezln he cleaned olf any oeeumulziled eur-hon hy simply luloliingv the end ol' the plug :ufr-oss n piece or rough cloth.

nolher object o1 the invention is ,lo pro- Ivide a spark plug whirh will he very .filgrong and in which the poreelain will noi: he liable to he. easily crm-lied it is not neeessery to folie the plug apart lo olefin the same,

A:mother ohifeel ol the invention is to provide n spark plug no constructed that i `will be" eusy to. nasi-,mille und when assenililedlio strong and durable and Very nervieouble when in use.

This invention is illust'rziled in them-,coinpanying drawings. wherein:

Figure l is u sel-rionul View through one form of the improved plug.

'Figure 2 is n riep' looking :it the end o? the plug as r-,onstrucied in lfig. l.

Figure'l is :i longiludiual Sectional View through n inodilied forni or" plug.

llfigure lis a further niodilieolion.

Figure un end View of the 'forni Shown in Fig.

The :spark plug in the forni shown in Figs. l and f2 is provided with n. shell or holly l haring one endv portion enlizlged lo provide a Wrench-enguging portion 52. he enlarged end portion being :lorrned infernzilly lo provide i Seuly Il and haring ithA outer portion threaded to receive lhe packing nul; i by means oli' which he porcelain will he firmly secured in place. Thie,l porcelain extends through the hodyv ani ,shown in Fig. l incl is provided 'Willi an outstanding angular shoulder 6 which will he engaged hy the packing nut l and thus che porcelain so 'eurely hut releuoahly held inplewe when the nut is tightened. *Gaskets o ure provided .upon the' porcelain as shown. so thut lhere will be no danger ol' the porcelain being and nre providi cracked and :further to provide a gas-tight joint when olie securing nul` is tightened.'

l0 which lzs upon the inner enel or' #ghe porcelrii'n ond :prei/'ined 'with neoencrol openl ing through which the reduced enel porion l1 of lelie porcelain. firing l2 oro Lend from this o oliopori control portion evenings through which ille securing Soren' poes ond into threaded Socleio orrneii inlv'he Shell. It snonlrl loe noeii their one openir @o 'inrongh which the extended or rerince'cl ond portion `of lire porcelain li' posees, is reloiively smell and *ehere'lfore e. very smell-Space will 'oe lei'; between ne eleerocle Ehe cup. This splice fio small -rhirf delle spnrlr may easily joinp :across he porcelain lo the bridge or electrode l() which is 'onori 5o faire einiger shell by screws i3. carbon ol' the porcelain between the electrode and .the hriflwe. .the urli would Jess liron lr rhe carbon as this would he llie point of resistance and this small deposit oi? carbon would hns be burnt. lll' however, o nulli (fieno quantity of carbon should gather upon the enel of the plug to interferewith proper operalion ori-lie plug. il; would simply he necessary lo remove the plug and 'rolo one bridge and end portion 'll of the plug along :i piece of eloihv or oiherrongh subsistence. This would serve to very solenni/ely remove the, carbon end would lenire the porcelain clean. lil for any reason, elli". slionlfl nccuinnlue in the specie between iblnetapered' end portion of olie porcelain 'and the' body portion of the plug, ihis will not interfere with rho proper inncoioning 'lille ping for long as lire end snrfoee il' remains olefin sind che porcelain holly is. not cracked, "che plug will uncion properly.

in lhelorin shown in Fig. 3., the porcelain 14 lilo within rind entirely lilla vhe major porion olt the Spark ping shell or body l5 and is provided Wih reduced enel por-lion 'lli which corresponds lo lilac enel. lll,

` ohonlcl gather upon one portion oli lie exi/ended, @nel extends through a email openinfgforned in' the body l5. rEhe end of the electr, de 17 terminetes iiush With the extended fend 16 of the porcelain and the porcelain isueh with the end oi the body i5. rifl'ierefore, the spark could jump easily across the Small circle oi porcelain. to the body of the plug. and carbon which may accumulate upon the porcelain could he easily wiped ot after the njnnnez" set forth in connection with the torni shown in Figs@` l and 2. 'in this form, the porcelain is held in placey by ineens oil a nut i8 similar to the nut Li which would be' removed when it is desired to remove the porcelain and either thoroughly clean it or replace it With a new one.

ln the forro shown in lligs. i and 5, the body or shell i9 oic the plug is similar inconstruction to the tonnjhown in Fig. l and the porceliiilleo of a construction sim-* ilar to that shown in Fig. l. This" porce-v lain is held in place by a securing nut 21 similar to the nut 4;. l` he porcelain in this form is extended beyond. the end of the shell and provided with a reduced end 22 which corresponds to the reduced end ll. instead of providing a bridgeor other similar structure, there has been provided a` cap or jacketl 23 whichiits upon the tapered end portion of the porcelain and is provided with a small opening in its outer end through Which-the` reduced end portion 22 of the porcelain extends with the end of the porcelain terminating flush with the end oi the cap and the electrode 2&5 terminating flush with the ey d of the porcelain. This cap is provided e its inner end with an4 outstanding flange or cellar 25 which is clamped f Leanne@ providing means for permitting the cap or' jacket to be securely held in place. It will thus he seen that in eachjl'orm the electrode terminates flush with the reduced end ot' the 'porcelain and this reduced end extends through a small opening so that the end of the electrode is separated from the metal leading to the body of the plug by a very si all space oi' porcelain across which the .spark can easily jump. lt will further he noted that in each forni the nlug providesi a structure which can be easily and quickly y cleaned but which in most cases will be sell cleaning and may be thoroughly cleaned by simply rubbing across a piece of' rough cloth.

I claim:

A spark plug comprising a body, a porcelain'eecured in said body and having a reduced end, an electrode extending through the porcelain and having its end terminating flush with the poreclain at the reduced end thereof7 and a bridge having a central portion fitting upon the porcelain and provided with an opening receiving the reducedxend there-olf, and the outer face of the central portion oi" the bridge being flush with the end of the porcelain, arms extending from the central portion of the bridge and connected with the body of the plug at the end thereof.

ln testimony whereof I aiix my signature.

ROBERT r. sTErnEn'soN. 

